JP7700604B2 - Power storage device - Google Patents

Description

This disclosure relates to an electricity storage device.

For example, JP 2014-24488 A discloses a battery unit including a battery case having a battery tray and a battery cover, multiple batteries arranged in the battery case, and a battery bracket that is a single plate and is fixed to the battery tray. The battery tray has a bottom wall, multiple ribs standing on the bottom wall, and multiple partition walls standing on the bottom wall.

JP 2014-24488 A

In the battery unit described in JP 2014-24488 A, if a load is applied to the case in the vertical direction, there is a concern that the load may be transferred to the storage cells.

The objective of this disclosure is to provide an energy storage device that can protect the energy storage cells from loads applied to the case in the vertical direction.

A storage battery device according to one aspect of the present disclosure includes a plurality of storage cells each arranged in one direction, and arranged in an orthogonal direction perpendicular to both the one direction and the vertical direction; a case for housing the plurality of storage stacks; and a protective structure provided within the case and protecting the plurality of storage cells from a load input in the vertical direction relative to the case. The case has a bottom wall arranged below the plurality of storage stacks, a top wall arranged above the plurality of storage stacks, and a peripheral wall that connects a peripheral portion of the bottom wall to a peripheral portion of the top wall and surrounds the periphery of the plurality of storage stacks. The protective structure is arranged on the bottom wall and between a pair of the storage stacks adjacent to each other in the orthogonal direction, and includes a cross member having a shape extending in the one direction and connected to the peripheral wall, and a load transfer member arranged on the cross member. The load transfer member is compressively deformable in the orthogonal direction and has at least one contact portion that contacts a pair of the storage stacks adjacent to each other in the orthogonal direction in a compressed state.

This disclosure provides an energy storage device that can protect the energy storage cells from loads applied to the case in the vertical direction.

1 is a perspective view illustrating a schematic configuration of an electricity storage device according to an embodiment of the present disclosure. 4 is a perspective view showing a schematic state before the power storage stack is placed on the lower case. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a plan view illustrating a schematic positional relationship between a load transmitting member and an intermediate plate. 4 is a cross-sectional view taken along line VV in FIG. 3.

Embodiments of the present disclosure will be described with reference to the drawings. Note that in the drawings referred to below, identical or equivalent components are given the same numbers.

Figure 1 is a perspective view that shows a schematic configuration of an energy storage device according to one embodiment of the present disclosure. The energy storage device 1 is mounted on, for example, a vehicle.

As shown in Figures 1 to 3, the energy storage device 1 includes multiple energy storage stacks 100, a case 200, and a protective structure 300.

As shown in FIG. 1, each storage stack 100 has a plurality of storage cells 110 arranged in one direction. An example of the storage cells 110 is a lithium ion battery. Each storage cell 110 is formed in a rectangular parallelepiped. As shown in FIG. 1, the plurality of storage stacks 100 are arranged in an orthogonal direction that is orthogonal to both one direction and the vertical direction.

Each storage stack 100 has a first unit stack 101, a second unit stack 102, and an intermediate plate 103.

The first unit stack 101 is arranged on one side in one direction. The first unit stack 101 includes some of the multiple storage cells 110. The first unit stack 101 may include an end plate. The end plate is arranged outside the storage cell 110 arranged on the outermost side in the one direction.

The second unit stack 102 is disposed on the other side in one direction. The second unit stack 102 includes storage cells 110 other than the storage cells 110 included in the first unit stack 101 among the multiple storage cells 110. In this embodiment, the number of storage cells 110 included in the second unit stack 102 is the same as the number of storage cells 110 included in the first unit stack 101. The second unit stack 102 may include an end plate disposed outside the storage cells 110 in one direction.

The intermediate plate 103 is disposed between the first unit stack 101 and the second unit stack 102. The intermediate plate 103 is disposed in the center of the power storage stack 100 in one direction. The intermediate plate 103 is made of synthetic resin or the like.

The case 200 houses multiple power storage stacks 100. The case 200 has a lower case 210 and an upper case 220 (see FIG. 3). Note that the upper case 220 is not shown in FIG. 1 and FIG. 2.

The lower case 210 has a shape that opens upward. The lower case 210 is made of metal, synthetic resin, or the like. The lower case 210 has a bottom wall 212, a lower surrounding wall 214, and a lower flange 216.

The bottom wall 212 is disposed below the multiple power storage stacks 100. As shown in Figs. 2 and 3, a raised portion 212a that rises upward is formed in the center of the bottom wall 212 in one direction. The top of the raised portion 212a is formed flat. As shown in Fig. 3, the intermediate plate 103 is placed on the raised portion 212a.

The lower surrounding wall 214 rises from the peripheral edge of the bottom wall 212 and surrounds the lower periphery of the multiple storage stacks 100.

The lower flange 216 has a shape that protrudes outward from the upper end of the lower surrounding wall 214.

The upper case 220 has a shape that opens downward. The upper case 220, together with the lower case 210, houses multiple power storage stacks 100. The upper case 220 is made of metal, synthetic resin, or the like. The upper case 220 has a top wall 222, an upper surrounding wall 224, and an upper flange 226.

The top wall 222 is disposed above the multiple power storage stacks 100. The top wall 222 may be formed in a flat plate shape. A gap is formed between the top wall 222 and each power storage stack 100.

The upper surrounding wall 224 extends downward from the peripheral portion of the top wall 222 and surrounds the upper periphery of the multiple power storage stacks 100. The upper surrounding wall 224 forms a peripheral wall together with the lower surrounding wall 214. The peripheral walls 214, 224 connect the peripheral portion of the bottom wall 212 and the peripheral portion of the top wall 222, and surround the periphery of the multiple power storage stacks 100.

The upper flange 226 has a shape that protrudes outward from the lower end of the upper surrounding wall 224. The upper flange 226 is fixed to the lower flange 216 by bolts or the like.

The protective structure 300 is provided in the case 200 and protects the multiple storage cells 110 from a load input in the vertical direction relative to the case 200. As shown in FIG. 3, the length of the protective structure 300 in the vertical direction is greater than the length of the multiple storage cells 110 in the vertical direction. As shown in FIG. 4, the protective structure 300 is disposed between a pair of intermediate plates 103 adjacent to each other in the orthogonal direction. In this embodiment, the protective structure 300 has a cross member 310 and a load transfer member 320. In FIG. 3, the first unit stack 101, the second unit stack 102, and the intermediate plate 103 are shown by two-dot chain lines, and in FIG. 4, the first unit stack 101 and the second unit stack 102 are omitted from the illustration. In reality, after the power storage stack 100 is assembled to the lower case 210, the load transmission member 320 is placed on the cross member 310, but for the sake of explanation, FIG. 2 shows the state before each power storage stack 100 is housed in the lower case 210.

The cross member 310 is disposed on the bottom wall 212. The cross member 310 has a shape that extends in one direction and is connected to the lower surrounding wall 214. In other words, the cross member 310 has a function of reinforcing the lower surrounding wall 214. The cross member 310 has a cross section in a plane perpendicular to the one direction that is formed into a shape that is convex upward. It is preferable that the upper surface of the cross member 310 is formed flat. The cross member 310 is disposed between a pair of power storage stacks 100 adjacent to each other in the perpendicular direction. In other words, the cross member 310 separates a pair of power storage stacks 100 adjacent to each other in the perpendicular direction.

The load transfer member 320 is disposed on the cross member 310. The load transfer member 320 transfers a load inputted downward relative to the top wall 222 to the cross member 310. The load transfer member 320 transfers a load inputted upward relative to the bottom wall 212 to the top wall 222. The load transfer member 320 is made of a synthetic resin or the like. As shown in FIG. 4, the load transfer member 320 is disposed between a pair of intermediate plates 103 adjacent to each other in the orthogonal direction.

2 and 3, the load transmission member 320 has a transmission member body 320A and a pair of positioning members 320B. The transmission member body 320A has a first pillar portion 321, a second pillar portion 322, and a connecting portion 323.

The first pillar portion 321 is disposed on the cross member 310. The upper end of the first pillar portion 321 may be in contact with the top wall 222 or may be spaced apart from the top wall 222. As shown in FIG. 3, a first engagement portion 321a is provided at the lower end of the first pillar portion 321, and this first engagement portion 321a is attached to a first mounting hole (not shown) provided on the upper surface of the cross member 310. Note that in FIG. 3, the first engagement portion 321a is shown by a solid line, although it should actually be shown by a dashed line.

The second pillar portion 322 is disposed on the cross member 310. The second pillar portion 322 is disposed at a position spaced apart from the first pillar portion 321 in one direction. The upper end of the second pillar portion 322 may be in contact with the top wall 222 or may be spaced apart from the top wall 222. As shown in FIG. 3, a second engagement portion 322a is provided at the lower end of the second pillar portion 322, and this second engagement portion 322a is attached to a second mounting hole (not shown) provided on the upper surface of the cross member 310. Note that in FIG. 3, the second engagement portion 322a is shown by a solid line, although it should actually be shown by a dashed line.

The connecting portion 323 connects the first column portion 321 and the second column portion 322. As shown in Figs. 3 and 4, the connecting portion 323 is disposed between a pair of intermediate plates 103 adjacent to each other in the perpendicular direction. The connecting portion 323 is provided with a through hole 323h that passes through the connecting portion 323 in the perpendicular direction.

Each positioning member 320B is located within a through hole 323h of the connecting portion 323 and is fixed to the connecting portion 323. Each positioning member 320B contacts a pair of adjacent power storage stacks 100 in the perpendicular direction across the transmission member body 320A, thereby determining the position of the transmission member body 320A between these power storage stacks 100. As shown in FIG. 3, each positioning member 320B has a center portion 326 and a contact portion 327.

As shown in Figures 3 and 5, the central portion 326 clamps the connecting portion 323.

The contact portion 327 is connected to the upper end of the central portion 326. The contact portion 327 is compressible and deformable in the orthogonal direction (left-right direction in FIG. 4). Specifically, the contact portion 327 has a shape that gradually curves upward as it moves away from the central portion 326 in the orthogonal direction and is convex downward. The contact portion 327 is supported in a cantilevered manner by the central portion 326. The contact portion 327 is in contact with a pair of power storage stacks 100 adjacent to each other in the orthogonal direction while being compressed in the orthogonal direction. The contact portion 327 receives a load input in the orthogonal direction to the peripheral walls 214, 224.

As described above, in the energy storage device 1 of this embodiment, when a downward load is applied to the top wall 222, the load is transmitted to the bottom wall 212 via the protective structure 300, and when an upward load is applied to the bottom wall 212, the load is transmitted to the top wall 222 via the protective structure 300. This prevents the load applied in the vertical direction to the case 200 from being transmitted to the energy storage cells 110.

Furthermore, since the load transmission member 320 has contact portions 327 that contact the pair of power storage stacks 100 in a compressed state, the load transmission member 320 is prevented from being displaced relative to the power storage stacks 100 and the cross member 310 due to vibrations or the like. This prevents abnormal noise caused by the load transmission member 320 colliding with the power storage stacks 100 and the cross member 310.

In addition, the assembly of the load transfer member 320 to the cross member 310 is completed by inserting the first engaging portion 321a and the second engaging portion 322a into the respective mounting holes of the cross member 310, making it easier to assemble the load transfer member 320 to the cross member 310. Also, it becomes easier to center the load transfer member 320 in the orthogonal direction when assembling it.

It will be understood by those skilled in the art that the exemplary embodiments described above are specific examples of the following aspects:

The energy storage device in the above embodiment includes a plurality of energy storage stacks, each of which includes a plurality of energy storage cells arranged in one direction, and which are arranged in an orthogonal direction perpendicular to both the one direction and the vertical direction; a case that houses the plurality of energy storage stacks; and a protective structure that is provided in the case and protects the plurality of energy storage cells from a load input in the vertical direction to the case. The case has a bottom wall that is arranged below the plurality of energy storage stacks, a top wall that is arranged above the plurality of energy storage stacks, and a peripheral wall that connects the peripheral portion of the bottom wall to the peripheral portion of the top wall and surrounds the periphery of the plurality of energy storage stacks. The protective structure is arranged on the bottom wall and between a pair of the energy storage stacks adjacent to each other in the orthogonal direction, and includes a cross member that has a shape that extends in the one direction and is connected to the peripheral wall, and a load transfer member that is arranged on the cross member. The load transfer member is compressively deformable in the orthogonal direction and has at least one contact portion that contacts the pair of the energy storage stacks adjacent to each other in the orthogonal direction in a compressed state.

In this energy storage device, when a downward load is applied to the top wall, the load is transferred to the bottom wall via the protective structure, and when an upward load is applied to the bottom wall, the load is transferred to the top wall via the protective structure, preventing the load applied in the vertical direction to the case from being transferred to the energy storage cells.

Furthermore, because the load transmission member has contact portions that come into contact with the pair of power storage stacks in a compressed state, relative displacement of the load transmission member with respect to the power storage stacks or the cross member due to vibrations or the like is suppressed. This suppresses the generation of abnormal noise caused by the load transmission member colliding with the power storage stacks or the cross member.

Furthermore, it is preferable that the length of the protective structure in the vertical direction is greater than the length of the multiple storage cells in the vertical direction.

It is also preferable that the at least one contact portion includes a pair of contact portions arranged at positions spaced apart from each other in the one direction.

It is also preferable that the load transmission member further includes a first column portion, a second column portion disposed at a position spaced apart from the first column portion in the one direction, and a connecting portion connecting the first column portion and the second column portion.

In this embodiment, the first and second pillars can transmit vertical loads at positions spaced apart in one direction, and because the first and second pillars are connected by a connecting part, the load transmission member can be handled more easily than when the first and second pillars are made of separate members.

It is also preferable that at least one of the contact portions is connected to the connecting portion.

It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is indicated by the claims rather than the description of the embodiments above, and further includes all modifications within the meaning and scope of the claims.

1 Energy storage device, 100 Energy storage stack, 101 First unit stack, 102 Second unit stack, 103 Intermediate plate, 110 Energy storage cell, 200 Case, 210 Lower case, 212 Bottom wall, 212a Raised portion, 214 Lower surrounding wall, 216 Lower flange, 220 Upper case, 222 Top wall, 224 Upper surrounding wall, 226 Upper flange, 300 Protective structure, 310 Cross member, 320 Load transmission member, 320A Transmission member body, 320B Positioning member, 321 First pillar portion, 321S First outer surface, 322 Second pillar portion, 322S Second outer surface, 323 Connection portion, 326 Center portion, 327 Contact portion.

Claims (3)

A plurality of power storage stacks each including a plurality of power storage cells arranged to be aligned in one direction, and arranged to be aligned in an orthogonal direction perpendicular to both the one direction and the vertical direction;
a case that houses the plurality of power storage stacks;
a protective structure provided within the case to protect the plurality of power storage cells from a load input in a vertical direction relative to the case,
The case is
a bottom wall disposed below the plurality of power storage stacks;
a top wall disposed above the plurality of power storage stacks;
a peripheral wall that connects a peripheral portion of the bottom wall and a peripheral portion of the top wall and surrounds the plurality of power storage stacks;
The protective structure includes:
a cross member disposed on the bottom wall between a pair of the power storage stacks adjacent to each other in the perpendicular direction, the cross member having a shape extending in the one direction and connected to the peripheral wall;
a load transfer member disposed on the cross member,
the load transfer member is compressively deformable in the orthogonal direction and has at least one contact portion that is in contact with a pair of the power storage stacks adjacent to each other in the orthogonal direction in a compressed state;
a length of the protective structure in a vertical direction is greater than a length of the plurality of storage cells in the vertical direction,
The at least one contact portion includes a pair of contact portions arranged at positions spaced apart from each other in the one direction . The load transmitting member is
A first pillar portion;
A second column portion disposed at a position spaced apart from the first column portion in the one direction;
The power storage device according to claim 1 , further comprising a coupling portion coupling the first pillar portion and the second pillar portion together. The power storage device according to claim 2 , wherein the at least one contact portion is connected to the coupling portion.

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